Technical Field
The present invention relates to an inkjet printing process using an ink set formed of two kinds of inks, and a non-aqueous ink set used in the inkjet printing process.
Related Art
An inkjet recording system is a print system in which printing is conducted by injecting a liquid ink having high fluidity from a fine nozzle to thereby allow the liquid ink to adhere to a recording medium such as paper. This system is a relatively inexpensive device and has a characteristic that it can print an image having a high resolution and a high quality at a high-speed with low noise, and thus has been spread rapidly in recent days.
Coloring materials for inks used in inkjet recording systems are roughly classified into those utilizing pigments and those utilizing dyes. Among these, inks using pigments as coloring materials tend to increase since they are excellent in light resistance, weather resistance and water resistance that are required for high-quality printing.
In terms of solvents, inks are roughly classified into aqueous inks and non-aqueous inks. Non-aqueous inks that do not use water as an ink solvent, including solvent-based inks containing a volatile solvent as the main constituent and oil-based inks containing a non-volatile solvent as the main constituent, have gained attention since they have characteristics that they have fine stability on printing machines (intermittent discharge property, discharge restoration property after leaving a long period, and the like), they cause no curl on printing papers, they require a short time for the permeation and drying of the inks, and the like (see, for example, Japanese Patent Application Publication No. 2003-261808 and Japanese Patent Application Laid-Open No. 2007-126564).